Buckle Folding Machine

ABSTRACT

A buckle folding machine with a plurality of parallel working rollers that are mounted together in a support that is rotationally mounted in the machine frame and that, via a drive, can be rotated for drawing in, folding, and ejecting the article to be folded, at least one of the rotating working rollers being displaceable, characterized in that the displaceable working roller as buckling roller ( 11 ) is a component of a radially movable buckling body ( 1 ) that can be tilted about a longitudinal axis that runs parallel to the working rollers ( 15, 16,  and  17 ), the buckling body ( 1 ) cooperating with the adjacent working rollers ( 15, 16,  and  17 ) for buckling the article ( 18 ) to be folded and for feeding it. to a folding gap and using at least one segment of a spreading cam ( 34 ) can be forcibly displaced into a position for permitting passage and into a position for buckling the article ( 18 ) to be folded.

The invention relates to a buckle folding machine with a plurality of parallel working rollers that are mounted together in a support that is rotationally mounted in the machine frame and that can be rotated by a drive for drawing in, folding, and ejecting the article to be folded, at least one of the rotating working rollers being displaceable.

The invention is based on prior art in accordance with WO 1994/008882 [U.S. Pat. No. 5,803,890], which is referenced herewith. In this known buckle folding machine, four working rollers with the same outside diameter are mounted together in one support that is rotationally mounted in a machine frame. A pair of feed rollers, also mounted in the machine frame, can be controlled via a slide of the support and cooperates with it during the drawing in and when the first fold is made. For drawing in, folding, and ejecting the paper, the support is rotated by a drive, one of the rollers. rotating therewith being displaceable by means of a cam and together with another working roller forming the second fold. The control is performed using the rotating support via an inside cam or in the case of completely electronic control via the working roller to support speed ratio. While the support is rotating, the paper is drawn in, folded, and ejected. The roller working in the drawing-in area is driven in opposition to the paper advance and therefore is covered with a guide body. This cover creates a large equipment diameter.

The object of the invention is to significantly reduce the dimensions of the known buckle folding machine and to increase its efficiency.

This is inventively attained in that the displaceable working roller as buckling roller is a component of a radially movable buckling body that can be tilted about a longitudinal axis that runs parallel to the working rollers, the buckling body cooperating with the adjacent working rollers, for buckling the article to be folded and for feeding it to a folding gap and using at least one segment of a spreading cam can be forcibly displaced into a position for permitting passage and into a position for buckling the article to be folded. Embodying the displaceable working roller as a buckling body results in about a 20% reduction in size of the structure of the buckle folding machine with four working rollers with the same outside diameter, since because the working roller located in the drawing-in area is omitted, the cover required through the opposing rotary direction is not needed.

Another inventive feature provides that the buckling body includes a mount and a buckling roller mounted rotatable therein, the mount covering the buckling roller along its longitudinal axis on at least one side.

In accordance with another feature of the invention, the mount of the radially displaceable buckling body can be displaced between the working rollers with one side that covers the buckling roller during the buckling process in order to feed the article to be folded to a folding gap.

Another feature of the invention provides that the mount of the buckling body is mounted via at least two compression springs relative to the mount such that the buckling body can be largely radially displaced against their spring force.

In accordance with another feature of the invention, the mount of the buckling body is provided with cylindrical bearing pins situated on both ends and on which control rollers are seated, the control rollers displacing the buckling body largely radially and against the force of the compression springs by rolling over a spreading cam that is mounted in the machine frame.

Another inventive feature provides that the bearing axle of the buckling roller is positioned offset from the bearing axle of the support and to the bearing axle of the control rollers, so that the buckling body can be tilted about the bearing axle of the support and so that also there is a press-fit connection between the buckling roller and a second working roller during the buckling process even for different thicknesses of articles to be folded. Another feature of the invention provides that provided adjacent the buckling body is a guide bar that runs with the support and that partially covers the adjacent working roller and that together with the buckling body forms a feed shaft for the article to be folded.

In accordance with another feature of the invention, a pair of feed rollers is provided that together with adjacent working rollers feeds the article to be folded into the machine in a known manner and makes the first fold in the article to be folded, the bearing axles of the pair of feed rollers being guided along the end disks of the support that are formed as a control cam. Mechanical control of the folding station is provided by the rotating support for the different types of folds and lengths of the articles to be folded, so that the article to be folded is drawn in, folded, and ejected during the step-wise or continuous rotation of the support.

Another inventive feature provides that the feed rollers are connected to one another via rocker elements, the rocker elements carrying a blocking surface that prevents the article to be folded from breaking out when the first buckling loop is formed between the feed rollers.

Additional advantageous features of the invention can be found in the description, claims, and drawings. The invention is described in greater detail in the following using a few illustrated embodiments and the drawings.

FIG. 1 is a longitudinal section through the mount of a buckle folding machine with two lateral support bearings and a view of the buckling body.

FIG. 2 is a cross section through the buckle folding machine in FIG. 1.

FIG. 3 is an inside view of the buckling body guide in the lateral disk and a top view of and view through the support bearing.

FIG. 4 is an end view of the rocker element.

FIG. 5 is an end view of the buckling body.

FIG. 6 is a longitudinal section through the buckling body in FIG. 5.

FIG. 7 schematically illustrates the position of the buckling body in the buckle folding machine when the article to be folded is advanced unimpeded.

FIG. 8 schematically illustrates the position of the buckling body in the folding machine during buckling.

FIGS. 9-14 each schematically illustrate the successive roller positions during a 360° folding process, along with each position of the buckling body including the article to be folded.

FIGS. 1 through 3 illustrate a buckle folding machine with stationary support bearings (12 and 13) in which a rotatable support (14) holds three parallel working rollers (15, 16, and 17) that cooperate with a buckling body (1), likewise moveably mounted in the support, and a pair of feed rollers (19 and 20), movably mounted in the lateral support bearings (12 and 13), when folding an article (18) to be folded. At both of their end faces the working rollers (15, 16, and 17) are provided with bearing axles (15 a, 16 a, and 17 a) that are rotationally mounted in the end disks (28 and 29) of the support (14). The support axes of the support are formed as a hollow shaft (30) and as a solid shaft (31) and are rotatably carried in the lateral support bearings.

The buckling body (1) illustrated in FIGS. 1, 2, 5, and 6 comprises a mount (2) (2) having spring guides (3) receiving compression springs (4), lateral mounting pins (5 and 6), bearing axles (7 a and 8 a) for rotationally mounting control rollers (7 and 8) and bearing sleeves (9 and 10) for receiving the bearing axles (11 a) of the buckling roller (11). The buckling body (1) is mounted in the support such that its two lateral mounting pins (5 and 6) and the bearing axles (7 a and 8 a) fit through two openings in the lateral disks (28 and 29) of the support (14) formed as buckling body guides (33), from inside toward the outside, and are forcibly and largely radially displaced by the control rollers (7 and 8) rolling on a spreading cam (34) against the spring pressure of compression springs (4) that are carried in the support on unloading elements (43). The rounded shape of the mounting pins (5 and 6) and the offset bearing axles (7 a and 8 a) of the control rollers (7 and 8) and of the bearing axle (11 a) of the buckling roller (11) permit a rocking movement about a rocking axis (35) of the buckling body in the buckling body guides (33). The spreading cam (34) is fixed or displaceable on the ends of the support bearings (12 and 13) that face the support (14). The support can be rotated manually or by a motor with a mechanical connection (not shown) to the solid shaft (31) via the support axis. Extending through the hollow shaft (30) illustrated in FIG. 1, is a roller drive shaft (36) that is formed as a solid shaft and that carries on its inner end a drive pinion (37) for driving the working rollers (15, 16, and 17) and is connected at its outer end via a gear to a motor or to a manually actuated drive apparatus (not shown). The drive pinion (37) mounted on the inner end of the roller drive shaft meshes with gears (38) of the working rollers (16 and 17). The two feed rollers (19 and 20) that function as drawing-in and buckling rollers have bearing axles (19 a, 20 a) that fit through the lateral disks (28 and 29) and are pressed by of tension springs (not shown) against the respective working rollers (16, 17, and 18), the control rollers (21, 22, 23, 24) seated on the bearing axles (19 a, 20 a) rolling on the control cams (27) of the lateral disks (28 and 29), these cams being formed as guide surfaces, and while the support (14) is rotating produce press-fit connections to the working rollers (16, 17, and 18) according to the control program. The leading feed roller (19) is moved via its bearing axles (19 a) in guides (40) in the support bearings (12 and 13). The trailing feed roller (20) is connected to the leading feed roller via rocker elements (25 and 26). When the first buckling loop is being formed in the area of the first folding gap between the working rollers (15) and (16) with their block surfaces (41), the rocker elements (25 and 26) prevent the article being folded from breaking out of the buckle folding machine through the gap between the feed rollers (19 and 20).

FIG. 7 and FIG. 8 illustrate a buckling body (1), forcefully radially displaced by an internal spreading cam (34) in a buckling body guide (33) provided in the lateral disks (28 and 29) against a spring force in the position for unimpeded transport of the article to be folded (18) and during a folding process. During radial displacement in the guides (33), the cylindrical design of the mounting pins (5 and 6) also enables a rocking movement over the rocker axis (35) of the buckling body (1) and thus due to the offset mounting of the bearing axle (11 a) of the buckling roller (11) a press-fit connection between the buckling roller (11) and the working roller (15) with a simultaneous buckling function. The buckling body, together with a guide bar (42) of the support (14), which bar runs with the support and partially covers the working roller (15), forms a feed shaft (39).

FIGS. 9 through 14 illustrate successive positions of the support in the buckle folding machine with the positions of the inventive buckling body (1) during a complete folding process. In principle different types of folds can be performed by the machine such as for instance a wrap fold or a Z-fold. The process for a wrap fold will now be used as an example. In this example the article (18) to be folded is fed via an upstream device (not shown here) between the pair of feed rollers (19 and 20) and the working roller (15) (see FIG. 9). After a precisely defined paper advance, the drive for the support (14) and for the working rollers (15, 16, and 17) begins to move. The arrows illustrate the directions of rotation for the rollers and for the support in FIGS. 9 through 14. The control cams (27) of the lateral disks (28 and 29), formed as guide surfaces, pivot the feed rollers (19 and 20) toward the support (14) where the article (18) to be folded situated between the guide rollers and the working roller (15) is made to move farther into the folding apparatus when the working roller (15) strikes the feed roller (19) (see FIG. 10). As the support continues to rotate, the constant translation ratio between working rollers (15, 16, and 17) and the support (14) causes the working roller (16) to strike the feed roller (19) at precisely the position at which, in connection with the oppositely driven working roller (15) and feed roller (20) for forming the first fold loop and for the working rollers (15) and (16) to draw it in, the article to be folded must be reversed against the advance direction (see FIG. 11). The buckling body (1), which in the meantime is guided largely radially outward by the spreading cam (34), permits further advance of the article (18) to be folded with the first fold edge on the front side (see FIG. 12). When the support (14) rotates further with the three working rollers (15, 16, and 17) and the buckling body (1), the latter, after passing the stationary spreading cam (34), due to the constant translation ratio, is returned by the compression springs (4) to precisely the location at which the article (18) to be folded must be returned for forming the second buckle loop in connection with the oppositely driven working roller (17). Because of the buckle body guides (33) in the lateral disks (28) and (29), the buckle body (1) is first guided to the working roller (15) with which the buckle roller (11) produces a press-fit connection and is driven thereby. In further succession the offset axles of the buckling body cause a rocking movement to the working roller (17), so that the article to be folded, which is guided freely between the working roller (17) and the buckling roller (11), is picked up and returned (see FIG. 13). The embodiment permits precise folding, even with different paper thicknesses. FIG. 14 illustrates the working rollers (16) and (17) that take up the buckling loop, fold the article (18) to be folded during further transport, and then eject it. The support (14) continues to rotate back to the starting position. 

1. A buckle folding machine with a plurality of parallel working rollers that are mounted together in a support that is rotationally mounted in the machine frame and that, via a drive, can be rotated for drawing in, folding, and ejecting the article to be folded, at least one of the rotating working rollers being displaceable wherein the displaceable working roller serving as buckling roller is a component of a radially movable buckling body that can be tilted about a longitudinal axis that runs parallel to the working rollers, the buckling body cooperating with the adjacent working rollers for buckling the article to be folded and for feeding it to a folding gap and using at least one segment of a spreading cam can be forcibly displaced into a position for permitting passage and into a position for buckling the article to be folded.
 2. The buckle folding machine in accordance with claim 1 wherein the buckling body includes a mount and a buckling roller mounted rotatable therein, the mount covering the buckling roller along its longitudinal axis on at least one side.
 3. The buckle folding machine in accordance with claim 2 wherein the mount of the radially displaceable buckling body can be displaced between the working rollers with one side that covers the buckling roller during the buckling process in order to feed the article to be folded to a folding gap.
 4. The buckle folding machine in accordance with claim 2 wherein the mount of the buckling body is mounted via at least two compression springs relative to the support such that the buckling body can be largely radially displaced against the spring force.
 5. The buckle folding machine in accordance with claim 2 wherein the mount of the buckling body is provided with cylindrical bearing pins situated on both ends and on which control rollers are seated, the control rollers displacing the buckling body largely radially and against the force of the compression springs by rolling over a spreading cam that is mounted in the machine frame.
 6. The buckle folding machine in accordance with claim 5 wherein the bearing axle of the buckling roller is positioned offset from the bearing axle of the support and to the bearing axle of the control rollers, so that the buckling body can be tilted about the bearing axle of the support and so that also there is a press-fit connection between the buckling roller and a second working roller during the buckling process even for different thicknesses of articles to be folded.
 7. The buckle folding machine in accordance with claim 1 wherein adjacent the buckling body is a guide bar. that runs with the support and that partially covers the adjacent working roller and that together with the buckling body forms a feed shaft for the article to be folded.
 8. The buckle folding machine in accordance with 1 wherein a pair of feed rollers is provided that together with adjacent working rollers feeds the article to be folded into the machine in a known manner and makes the first fold in the article to be folded, the bearing axles of the pair of feed rollers being guided along the end disks of the support that are formed as a control cam.
 9. The buckle folding machine in accordance with claim 8 wherein the feed rollers are connected to one another via rocker elements, the rocker elements carrying a blocking surface that is arranged to prevent the article to be folded from breaking out when the first buckling loop is formed between the feed rollers. 